SIM Card stand for the Subscriber Identity Module. A SIM card is also called a smart card which stores the identification information of the user. The SIM card points a smartphone to a specific mobile network. The SIM card holds all the data of the user. This includes user identities, location and phone numbers, network authorization data, personal security keys, contact lists and archived text messages. Without a SIM card, you cannot make or receive calls. You cannot enjoy internet and messaging without a SIM card. SIMs are computer chips that hold user information and allow you to connect to your network. With which you can make calls, send SMS messages to people and also take advantage of mobile internet services like 3G, 4G and 5G. A SIM card just looks like a small piece of plastic. The important part is a small integrated chip that can be read by the mobile device it is inserted into, and contains a unique identification number, phone number, and other data specific to the user who has registered for it. The first SIM cards were roughly the size of a credit card and were the same size around all the edges. Now, both the Mini and Micro SIM cards feature a cut-off corner to help prevent wrong insertion into the phone or tablet.
Types Of Sim Card by Technology
GSM: In today's time, the SIM card we use in mobile phones is GSM only. GSM SIM is the most commonly used SIM. You can use this type of SIM in different types of mobile phones by changing it.
CDMA: CDMA capable phones do not require a SIM card. As such, mobile devices use an electronic serial number (ESN). Users who have a phone with an ESN cannot easily switch between devices as users would need permission from their network carrier.
How does SIM card work?
Basically, a SIM card acts as your phone's identity card to access carrier networks. Because the SIM holds this information, you can pop it into any phone with the same carrier, or an unlocked phone, to access the network. The data stored on the SIM card includes a unique serial number called ICCID, International Mobile Subscriber Identity (IMSI), security authentication information, temporary information about the network, a personal identification number or PIN, and a personal unblocking code for unlocking or Includes PUK.